The present invention relates to a cutting insert for a cutting or breaking tool, which can be mounted in a tool holder that can be rotated about a longitudinal axis, and especially to a lathe chisel as well as to such a cutting or breaking tool itself.
Such tools are rotatably mounted in tool holders, which are usually fastened to a surface of a rotating roller. In the case of tools known in practice, heads of tool bodies and intermediate regions of cutting inserts are conical and constructed with a round cross section. A different hard alloy insert, described in the WO 94/13932, has a ribbed intermediate region, as a result of which an improved spatial behavior is to be attained, since the regions between the ribs serve to carry away material that has been cut off or broken off. However, because the material to be processed generally contains tar, the spaces between the ribs clog up quickly, so that the improved spatial behavior exists for only a short time.